I don't think it's likely that Mike Pence or Paul Ryan will take Trump's place. But if there's even a 10% chance of that happening, then there's probably at least a 6% chance of one of them winning, making this an appealing longshot. Pence is, of course, more likely than Ryan, but his relative likelihood is already priced in (as with all bets, you're betting not on likelihood, but on other people's miscalculation of likelihood).

To hedge, buy "yes" to "Will Hillary Clinton win the 2016 U.S. presidential election?", currently costing 80¢ for a $1 payoff.

You'll very, very likely make 20¢ on your dollar (minus whatever you bet on the longshots), with a potential huge kicker.

I don't like Ryan's or Pence's politics, but a win by either of them would go a long way toward healing the country. There's nothing like a bona fide bogeyman to put in perspective who our real collective enemies are.

Post-Debate Update: Hillary declined to go in for the kill again and again, ceding Trump myriad petty victories, steering him away from total meltdown and leaving him strong enough to retain GOP support. Pence, who'd taken two days off campaigning and was said to have been closely watching the debate to decide his future with the campaign, released a strong reassertion of support. So, crisis averted...on both sides. The Dems are understandably reluctant to shake dice when both presidency and Senate seem easily attainable, and the Trump campaign will limp on. So Pence/Ryan are no longer smart long-shot bets. So never mind!